Historic California Posts, Camps, Stations and Airfields
San Nicholas Island Radar Site J-42
 
 
History
 
Established in March 1942 this Army Air Forces air defense radar site was located on San Nicholas Island, on the ridge above San Nicholas Island Army Air Field/Naval Auxiliary Air Station San Nicholas Island (33°13'57.19"N 119°28'49.40"W). Assigned to the Los Angeles Control Group, this operated the radar systems identifield below:
 
 
Radar Sets on San Nicholas Island
 
SCR-270-D Mobile Long Wave Aircraft Warning Set
 
 
Description: Six-vehicle mobile, long wave early warning aircraft detector. Azimuth and range supplied. Set is equipped with "A" scope.
Uses: To establish a screen of warning which provides information of approaching aircraft as early as possible but with a sacrifice of accuracy in range, azimuth and elevation. IFF equipment RC-150 is used.
Performance and Siting: Maximum range on a single bomber flying at indicated heights, when set is on a flat sea level site:
 
 Altitude, feet  1,000  5,000  20,000  25,000
 Range, miles  20  50  100  110
Set should be sited at a height between 100' and 1000' above an unobstructed reflecting surface.
 
Transportability: Complete set is carried in 6 vehicles, the largest of which measures 30'4" x 9'10" x 8'. Total weight of shipment is 101,790 lbs; total volume 11,485 cu. ft.
Installation: Operates from trucks in which mounted. Can be placed in operation about 6 hours after arrival at site.
Personnel: Seven men comprise operating crew. For 24 hour operation about 50 men are required to run radar, communication radio, and camp.
Power: 15.3 KW, supplied by PE-74, 25 KVA gasoline-driven generator, having fixed consumption of 4 gal. per hour, non-leaded gasoline.
 
 
 
SCR-271-D and SCR-271-E Fixed Long Wave Aircraft Warning Set
 
Description: Fixed long wave early warning aircraft detector. Azimuth and range supplied on "A" scopes. 271-D has a 100' tower; 271-E, a 50' tower.
Uses: To establish a screen of warning which gives data on aircraft as early as possible, but with a sacrifice of accuracy in range, azimuth and elevation. IFF equipment RC-151 is used.
Performance and Siting: Maximum range on a single medium bomber flying at indicated altitudes, when set is on a flat sea level site:
 
 Altitude, feet  1000  5000  20,000  25,000
 SCR-271-E Range, miles  20  50  100  110
 SCR-271-D Range, miles  25  60  120  135
Sets should be sited so that the mean antenna height is between 100 and 1000 ft. above an unobstructed flat surface. The 100' tower should be used when it is desired to get additional low coverage, or to insure clearance above surrounding trees or other obstructions.
Transportability: Sets are packed in 106 units, weighing a total of 42,279 lbs. Largest unit is 176" x 25" x 20". Total volume is 4008 cu. fit.
Installation: Requires a weatherproof building approx. 20' x 40' for housing radar components and a building approx. 20' x 20' for housing the power units and switchboard. A 100 foot tower on concrete footings is required for an SCR-271-D and a 50-ft. tower for an SCR-271-3. Buildings and tower are built by engineers in about 3 weeks. Radar can be installed by five men in about two weeks.
Personnel: 7 men are operating crew. For 24 hour operations, about 50 men are required for radar, communication radio, and camp.
Power: 15.3 KW supplied by PE 74, 25 KVA gasoline-driven generator. Consumption is 4 gal. per hour, non-leaded standard commercial gas.
 
 
SCR-588 Long Wave Aircraft Detector and Ground Control Intercept Radar

 
Description: Fixed medium-range, long wave aircraft detector and GCI. Provides azimuth, range, and altitude data. Type HR and PPI scopes.
 
Uses: To give continuous plan position and accurate relative height of enemy plane and friendly fighter plane for GCI. Set can also be used for early warning and to give increased coverage at low angles of search. IFF equipment RC-188 is used. When operating as GCI, VHF equipment SCR-624 is required.
 
Performance and Siting: Maximum range on a medium bomber, with set on flat sea level site:
 Altitude, feet

 1,000

5,000

10,000

 25,000
 Range*, miles

 20

 50

 95

 105
*Range of PPI limits GCI operation to about 45 miles.
 
When operating as GCI, set must be sited so that a flat unobstructed surface extends at least 1/4th mile in the height-finding sector. Good GCI sites are extremely rare. For early warning, sets should be sited between 100 and 1,000 feet above an unobstructed surface.
Transportability: Set is packaged for shipment in 55 units, weighing a total of 54,000 lbs. Largest unit measures 15.3' x 3.8' x 1.8'. Total shipping space is 3500 cu. ft.
 
Installation: Requires a weatherproof building approximately 20' x 40' for housing radar components and a building approximately 20' x 20' for power units and switchboard. A 25' tower on concrete footing is required for support of antenna. Buildings and tower can be built by Engineers in about 3 weeks. Radar can be installed by 5 men in 2 weeks.
 
Personnel: 8 men are operating crew. For 24-hour operation about 54 men are required to run radar, communication radio, and camp.
 
Power: 4 KW at 230 volts and 1 KW at 115 volts, from three PE-198 electric diesel units, supplied with set. (Two units operate simultaneously). Fuel consumption is 21/2 gals. of Diesel fuel oil per hour.
 
 

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Posted 11 April 2016